1. Field of the Invention
This invention relates to disk information recording medium and information processing device capable of recording and reproducing data such as magnetic disk and optical disk data, and relates in particular to a digital data recording and reproducing device capable of recording and reproducing digital data for preventing the illegal recording or illegal reproducing of audio-visual data reproduced or recorded on a magnetic disk device by a personal computer after being received or accepted by way of a network, broadcast or other record medium, in order to protect the copyrights of the writer or author.
2. Description of the Related Art
In recent years, information such as music and video is being distributed by way of networks and broadcasts, received via means such as the Internet, and shown on displays such as the personal computers of individuals, or spread by network data distribution systems and recorded onto devices such as magnetic disk devices and magneto-optical disc devices connected to personal computers.
Users having for instance, a personal computer connected to the Internet may show the received digital information from the Internet on a display and such actions are generally understood to be allowed by the copyright holder of the information being presented. However, recording such information on a magnetic disk, optical disk or other record medium requires the special consent of the copyright holder. In order to restrict the recording of distributed information onto the magnetic disk, optical disk or other record medium of an individual, a key for instance is stored beforehand to indicate whether or not recording of the information onto a disk device is allowed. This key is configured to certify whether or not that disk is a legitimate device, in other words, whether the device has been granted a license from the provider of the information. When certified as a legitimate device, the recording of information onto that disk device is allowed.
Characteristic information (ID information) for identifying the information recording device or the record medium is embedded in the system receiving the transmitted information, as a method to certify whether or not the device of the receiver is the device that received appropriate consent, or in other words that the device used by the receiver is correctly licensed to receive, and record or reproduce that information transmitted from the information provider.
During distribution of the information, the provider of the information checks between the provider side and information receiver device whether or not the device is legitimately licensed based on the characteristic information (ID information). If verified that that the device is a legitimate device, then recording is performed normally, and if not a legitimately licensed device then recording is not performed.
In an alternative method, the recording of information is allowed on any device whatsoever and the reproduction (or playback) of illegal copies prevented by making a check for the license during information reproduction.
Characteristic information (ID information) to identify the medium or the device, is recorded prior to shipment at a specific position on the data recording section of the medium so as not to overlap.
The above configuration to prevent illegal copying is shown in FIG. 11, in a typical data communication by way of a communications network such as the Internet.
In the drawing in FIG. 11, an information provider 1100 is connected to a plurality of information receiving users 1101, 1102, and 1103, in a configuration capable of mutual exchange of information.
The user attempting to record information received from the information provider 1100 on a storage device such as the hard disk of the user's personal computer, makes a data distribution request to the information provider 1100 by way of the network, and the user transmits his own ID to the information provider 1100.
When the information provider 1100 receives the ID from the user, the ID is then compared with ID registered in the registered ID data base 1120, and if the user ID matches the data in the registered ID data base 1120 then the data distribution request is treated as a request from a genuine licensed user, and data (P) is extracted from the data base 1110 and provided to the user. In this case, the data can be transmitted for instance as encoded data.
When results of a comparison of the ID from the user with the ID stored in the registered ID data base 1120 do not show a match, then the data request is determined not to be a request from a genuine licensed user, and data is not sent.
In this kind of a system, the information receiving users 1101, 1102, 1103 are generally individual personal computers, and the system comprises a device such as magnetic disk devices capable of recording data and having data communication means. The user ID may be an ID created by the user, or an ID recorded beforehand as system characteristic information (ID information) prior to shipment, in a specified position of the data recording section of the medium.
The information provider 1100 is linked to the user beforehand by the license and in such cases, the characteristic information (ID information) of the information receiving users 1101, 1102, 1103 is registered in the registered ID data base 1120. The information provider 1100 compares the ID information transmitted from the information receiving users 1101, 1102, 1103 with the registered ID data, and decides whether or not the user transmitted ID matches the registered ID data. If the user ID and registered ID are a match, then the user is recognized as a legitimate user, and for instance, the distributed information is encoded with a specified key k, and this key transmitted to the information receiving users 1101, 1102, 1103.
A value obtained by applying a specific function f to the device ID transmitted by any of the information receiving users 1101, 1102, 1103 can be generated as the key: k (=f (ID). In the same way, on the information receiver side, a constant f can be applied to the ID to generate a key: k (=f (ID). Then, by utilizing that key k, the encoded music or video data transmitted from the information provider can be decoded.
However, in the conventional art, the characteristic information (ID information) for the information receiver device possessed by the user is an ID that was set by the user, or an ID recorded prior to shipment, on a specified position of the data record section of the medium. These kinds of ID that are set as desired by the user or are recorded prior to shipment, on the data record section of the medium are capable of being easily rewritten. Since ID recorded on the data section of the record medium such as a hard disk are capable of easily being rewritten by user operation from the host computer, the ID is vulnerable to alternation or falsification.
To prevent alteration to produce an illegal (false) ID, a program may be used for instance to control the disk drive so that rewriting of the section recorded with the ID information is impossible. However, the person attempting to make an illegal copy might use methods such as rewriting that control program so the possibility of rewriting data in that area still remains.
An illegal user therefore, might rewrite an ID held in an electronic device, changing the ID to the ID of a user possessing a genuine license so that the illegal user can then make an illegal recording of received data. Also, by copying a genuine ID to a plurality of devices, the possibility arises of a plurality of devices being capable of making illegal recordings of received data.
Therefore, the method of recording ID information on the data section of a medium in the system of the conventional art had the problem that illegal copying cannot be prevented. Furthermore, methods to make altering the ID difficult by recording characteristic (ID) information on the servo information record area in the medium or the device were proposed but even if altering the characteristic ID on a record medium became impossible, characteristic (ID) information such as the serial number of the magnetic disk was public information so that illegal users not having a genuine licensed disk device might steal the characteristic ID of the record medium of another party holding a genuine license, present the illegally acquired genuine ID to the information provider as if they were licensed user, and then acquire information illegally.
Another problem with the related art is that if characteristic ID information of a medium is received for instance via a broadcast or network, then that ID information can be altered or changed to the ID information of another device or medium and illegal copying then performed on that medium or device.